52 
them to your collection ; but on this condition, that, in your next 
letters, you favour us with some information, respecting these won- 
derful bodies, which have actually passed, from the vegetable to the 
mineral kingdom. 
Yours, &c. 
LETTER VII. 
VEGETABLE FOSSILS FOSSIL TREES DESCRIBED BY THE 
ANCIENTS BY THE MODERNS FOUND IN ALMOST EVERY 
PART OF THE WORLD. 
It has been my endeavour, in my preceding letters, to furnish you 
with some general and useful notions, respecting secondary fossils 
in general; as well as with some general account of those sub- 
stances, which will be found most frequently concerned, in the 
important changes which secondary fossils have undergone. 
Vegetable fossils will now, very properly, according to the 
arrangement I have adopted, become the subjects of our investi- 
gation. This also will be the proper moment for their consideration; 
since the curious phenomena you lately beheld, have, it is evident, 
considerably excited your curiosity and interest, respecting their 
particular changes. 
Vegetable fossils*, I shall divide into the following orders : — 
* Phytolithi, of Linnaeus and Wallerius. 
( 
